Communication with an implantable medical device during implantation

ABSTRACT

A system and method are described for delivering an implantable medical device in a patient and through a catheter. The delivery catheter comprises telemetry means for communicatively coupling the implantable medical device with an external instrumentation during implantation.

This application claims the benefit of U.S. Provisional Application No.61/291,098, filed on Dec. 30, 2009. The entire disclosure of the aboveapplication is incorporated herein by reference.

TECHNICAL FIELD

The disclosure relates generally to communication with an implantablemedical device during implantation.

BACKGROUND

A wide variety of implantable medical devices (IMDs) that deliver atherapy to or monitor a physiologic or biological condition of apatient, or both, have been clinically implanted or proposed forclinical implantation in patients. An IMD may deliver therapy to ormonitor a physiological or biological condition with respect to avariety of organs, nerves, muscles or tissues of the patients, such asthe heart, brain, stomach, spinal cord, pelvic floor, or the like. Thetherapy provided by the IMD may include electrical stimulation therapy,drug delivery therapy or the like.

The IMD may exchange telemetry communications with one or more otherdevices. The IMD may exchange telemetry communications with an externaldevice, such as a programmer device or a patient monitor (e.g., eitherattached to the patient or otherwise located near the patient). Thisinformation may be previously stored or real-time information. The IMDmay also receive information from another device, such as theprogrammer, via telemetry communication. Telemetry communication,however, requires a considerable current drain as compared to thecurrent drawn during non-telemetry operations during the service life ofthe IMD. As such, extensive telemetry communication with the IMD drainsthe power source of the IMD of valuable energy that could otherwiseextend the service life of the IMD.

Some IMDs may include one or more leads that extend from the IMD to atarget location of a patient, e.g., target organ, nerve, muscle ortissue of the patient. In one example, the IMD may include one or moreleads that extend to target locations within a heart of the patient.Other IMDs, however, may be sufficiently small that the IMD may beplaced directly at the target location without the need for one or moreleads extending from the IMD. Such a device may be referred to as aleadless IMD.

During implantation of an IMD that utilizes a conventional lead(s), theproximal end of the lead(s) is first connected to an analyzer to verifygood connection to a target location which is suitable for stimulationand/or detection as well as intact conduction and insulation along thelead. The analyzer may be a stand alone external instrument orintegrated within other instrumentation such as a programmer or cardiacnavigation system. During implantation of an IMD without conventionalleads (e.g., using a delivery catheter), wireless telemetrycommunication between the IMD and an external device is used to verifygood connection to the target location suitable for stimulation anddetection. This is because the IMD may not have a connection readilyavailable for use with an analyzer.

SUMMARY

This disclosure describes techniques for communicating with a leadlessIMD during implantation of the IMD within a patient. A system and methodare described to conserve energy in the IMD power source duringimplantation, thus extending a service life of the IMD. A catheter baseddelivery system for the IMD allows communication with the IMD duringimplantation. If the IMD has an electrode, the IMD can be used fortesting the electrode to determine whether the device and specifically,its electrode, is suitable for implant prior to disconnecting the IMDfrom the delivery system. In an alternative embodiment, a system isdescribed which temporarily connects the IMD to external apparatus andallows a direct connection to the electrode for testing suitability ofimplant. In some instances, the IMD can derive power from the telemetryand be used in the awakening process after manufacture.

In one example, this disclosure is directed to an implantable medicaldevice delivery system comprising an elongate catheter body having aproximal end and a distal end, a first telemetry coupling member locatednear the distal end of the catheter body; and a feed line coupled to thetelemetry coupling member. The implantable medical device deliverysystem further includes an implantable medical device detachably coupledto the distal end of the catheter body, wherein the first telemetrycoupling member is communicatively coupled to a second telemetrycoupling member of the implantable medical device.

In another example, this disclosure is directed to a method ofcommunicating between an external device and an implantable medicaldevice comprising carrying a communication signal via a feed line thatextends between the external device and a first telemetry couplingmember located within a delivery catheter and communicatively couplingthe communication signal between the first telemetry coupling member ofthe delivery catheter and a second telemetry coupling member of theimplantable medical device that is detachably coupled to the deliverycatheter.

In a further example, this disclosure is directed to an implantablemedical device delivery system comprising means for communicativelycoupling a communication signal with an implantable medical device thatis detachably coupled to a catheter and means for carrying acommunication signal between a proximal end of the catheter and thecoupling means located within the catheter.

This summary is intended to provide an overview of the subject matterdescribed in this disclosure. It is not intended to provide an exclusiveor exhaustive explanation of the techniques as described in detailwithin the accompanying drawings and description below. Further detailsof one or more examples are set forth in the accompanying drawings andthe description below. Other features, objects, and advantages will beapparent from the description and drawings, and from the statementsprovided below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual diagram illustrating an example medical system inwhich a telemetry device is connected via a feed line to a telemetrycoupling member placed in proximity to an IMD within a catheter.

FIG. 2 illustrates an example external device comprising a telemetrymodule, an analyzer module, a localization module and a display module.

FIG. 3 is a schematic diagram illustrating an example IMD which has beenexpelled from a catheter. The IMD is communicating with an externaldevice.

FIG. 4 is a schematic diagram illustrating an example IMD which has beenexpelled from a catheter. The IMD is communicating with another IMD.

FIG. 5 is a schematic diagram illustrating a telemetry coupling memberon the distal end of a catheter, the telemetry coupling member adjacentto an IMD.

FIG. 6 is a conceptual diagram illustrating detail of the distal end ofan example catheter with an antenna and feed line embedded in the bodyof the catheter.

FIG. 7 is a conceptual diagram illustrating detail of the distal end ofan example catheter with a feed line and an antenna surrounding an IMD.

FIG. 8 is a conceptual diagram illustrating detail of an example distalend of a catheter with a feed line and a planar antenna.

FIG. 9 is a conceptual diagram illustrating an example catheter, adelivery module and an IMD.

FIG. 10 a is a schematic diagram illustrating an example deliverycatheter with direct electrical connections.

FIG. 10 b is a conceptual diagram illustrating detail of the example IMDin FIG. 10 a.

FIG. 11 a is a conceptual diagram illustrating an example deliverycatheter with a capacitive connection between a feed line and an IMD inthe distal end of a catheter.

FIG. 11 b is a conceptual diagram illustrating detail of the example IMDin FIG. 11 a.

FIG. 12 is a conceptual diagram illustrating an example deliverycatheter with a transducer.

FIG. 13 is a schematic diagram illustrating an example IMD connected toan external device.

FIG. 14 is a schematic diagram illustrating an example catheter havingtelemetry coupling electrodes.

FIG. 14 a is a schematic diagram illustrating another example catheterhaving telemetry coupling electrodes.

FIG. 15 is a schematic diagram illustrating an example delivery systemutilizing body electrodes on a patient.

FIG. 16 is a schematic diagram illustrating the example delivery systemof FIG. 15 within IMD expelled from a delivery system catheter.

FIG. 17 is a schematic diagram illustrating an example delivery systemcatheter having a telemetry coupling member and telemetry couplingelectrodes.

FIG. 18 is a schematic diagram illustrating an example delivery systemwith a plurality of electrodes placed on the body of the patient.

FIG. 19 is a schematic diagram illustrating an example IMD that may bedelivered via a catheter.

FIG. 20 is a state diagram of four states and transitions between thosestates.

FIG. 21 is a schematic diagram illustrating an example IMD with directelectrical power connections.

FIG. 22 is a schematic diagram illustrating an example IMD with directelectrical telemetry connections.

FIG. 23 is a schematic diagram illustrating an example IMD withtelemetry electrodes.

DETAILED DESCRIPTION

Some IMDs for delivering a therapy and/or monitoring a condition of apatient are sufficiently small such that the IMD may be placed directlyat the target location without the need for one or more leads extendingfrom the IMD and connecting the IMD to the target location. Such IMDs,which may be referred to as leadless IMDs, are typically implantedwithin a patient using a delivery catheter. The delivery catheter may bedesigned to deliver the IMD into the body of the patient. The catheteris indwelling, that is, it is placed at least partially into the body ofthe patient to deliver the IMD from outside the patient to inside thepatient. Various techniques are well known for gaining access to theinterior of the patient utilizing the cardiovascular vessels and otherspaces within the body. In the example of cardiac rhythm managementdevices, the Seldinger technique may be used to access the patient'svenous anatomy. Puncturing the skin below the xiphoid process may alsobe used to gain access to the pericardial space. The techniques justmentioned generally do not require general anesthesia nor do theyrequire depressing respiratory function. However, any of a variety ofother techniques may be used to gain access to the interior of thepatient. Placement of small medical devices via a catheter may avoid theundesired cosmetic effects associated with the placement of similardevices placed through an incision in the skin, especially for theslender patient.

The catheter used for introduction and placement of an IMD may have thecapability of being controlled external to the patient such that thecatheter may be steered or pointed. The catheter is used to move the IMDto a suitable site for implantation. The suitable site for implantationmay be referred to in this disclosure as a target location within thepatient, and may include, a target organ, tissue, nerve, muscle or otherlocation. Instrumentation may be provided for assessment of potentialimplant sites. Upon locating a suitable site for implantation, the IMDmay be attached or located in the body in a manner such that it mayremain affixed in the desired location.

FIG. 1 is a schematic diagram illustrating an example implantablemedical device delivery system 8 for implanting an IMD 14 at a targetlocation within a patient 10. Delivery system 8 includes a deliverycatheter 20 that is placed partially within patient 10 via access site12. The demarcation of access site 12 identifies the location at whichthe delivery catheter 20 transitions from outside patient 10 to insidepatient 10. Although access site 12 is shown in FIG. 1 to be located ina chest area of patient 10, access site 12 may be located anywhere onthe body of patient 10.

Delivery catheter 20 comprises an elongate catheter body 21 having aproximal end and a distal end. In the example illustrated in FIG. 1, thedistal end of catheter body 21 is located within the body of patient 10and the proximal end of catheter body 21 is located outside of the bodyof patient 10. Catheter body 21 may be constructed of soft, flexiblematerials such as silicone rubber or various elastomers. Deliverycatheter 20 further comprises a telemetry coupling member 22 locatednear the distal end of catheter body 21 and a feed line 16 that extendsfrom telemetry coupling member 22 to the proximal end of catheter body21. Feed line 16 carries telemetry signals to and from telemetrycoupling member 22.

Delivery catheter 20 may also include IMD 14 detachably coupled to thedistal end of catheter body 21. IMD 14 may be placed in the deliverycatheter 20 before delivery catheter 20 is placed at least partiallywithin patient 10. For example, delivery catheter 20 may be shipped to aphysician with IMD 14 placed within delivery catheter 20. As anotherexample, delivery catheter 20 may be shipped to a physician without IMD14 placed within delivery catheter 20 and the physician may place IMD 14into delivery catheter 20 before delivery catheter 20 is received inpatient 10. Alternatively, IMD 14 may be delivered from outside patient10 to inside patient 10 through delivery catheter 20 after deliverycatheter 20 is placed at least partially within patient 10.

IMD 14 may include appropriate circuitry and/or components fortherapeutic and monitoring objectives during the service life of IMD 14.As will be described in further detail below, IMD 14 may, in oneexample, comprise one or more sensing components, therapy deliverycomponents, telemetry components, power sources, memory components andthe like. IMD 14 will be described in this disclosure as an implantablecardiac pacemaker for purpose of illustration. However, IMD 14 could beany of a number of medical devices intended for implantation inpatients, such as a cardiac defibrillator, cardioverter and/or cardiacresynchronization device, a neurological stimulator, monitoring devicesfor a variety of physiological parameters, a pump for administering adrug or a biologic, or a replacement valve. The use of a cardiacpacemaker is illustrative of the concept but does not limit theapplicability of the techniques as described herein.

Delivery catheter 20 may include a steering mechanism (not shown) thatallows operator to steer catheter 20. The steering mechanism may includeone or more pull wires. These comprise a wire or multiple wires placedin the wall of catheter body 21 and may be connected to various leversat the proximal end, outside of the body. Delivery catheter 20 mayfurther include additional wires placed through a lumen formed bycatheter body 21 or within the walls of catheter body 21 to performother functions. For example, an additional wire from the proximal endto the distal end may allow an operator to push IMD 14 from the distalend of catheter 20 and eject it from delivery catheter 20. With acombination of wires and levers, the additional wires may allow theoperator to rotate IMD 14 to affix IMD 14 to the target location. Such amechanism is illustrated in FIG. 1 with reference numeral 6. The pullwires in delivery catheter 20 may also be utilized for electricalconduction. In this embodiment, the pull wires might also be used asfeed line 16 for telemetry communication and/or as control lines forconnection to the analyzer module in the external device 18 (shown inFIG. 17 and discussed below) or to send power to/from the IMD or forconnection to sensors placed within the delivery catheter 20 (shown inFIGS. 10 a, 10 b and discussed below).

An external device 18 shown in FIG. 1 may also be part of deliverysystem 8. As illustrated in FIG. 2, the external device 18 comprises oneor more of a telemetry module 26, an analyzer module 27, a localizationmodule 28 and a display module 29. Telemetry module 26 may generate,receive and/or test telemetry communication signals for communicatingwith IMD 14. Analyzer module 27 may generate signals, receive signals,and direct testing measurements to assess the suitability of anelectrode for implant considering the intended therapeutic use,monitoring use and telemetry communication. Localization module 28 mayidentify the position of IMD 14 or the electrodes of IMD 14 or otherelectrodes that are in or on the body of the patient 10. Display module29 may present information for the clinician operator during a procedureusing the external device, including information regarding the telemetrycommunication, testing, position, or other information. These modulesand their functions are described below in further detail. Whileexternal device 18 of FIG. 2 is depicted comprising all four modules inone device, external device 18 may include only a portion of the modulesand/or more include additional modules. Moreover, external device 18 mayfurther comprise one or more separate devices, e.g., a telemetry device,an analyzer device, a localization device and/or a display device. Inthis manner, the modules of external device 18 may be constructed andcombined in other combinations or all four could be separate.

Referring back to FIG. 1, during the navigation and delivery of IMD 14,it may be desirable for external device 18 to communicate with IMD 14.External device 18 may, for example, communicate with IMD 14 to causeIMD 14 to perform one or more actions including retrieving informationverifying that the location of IMD 14 is suitable for one or more ofstimulation, detection and telemetry communication. External device 18of FIG. 1 is connected to feed line 16 at the proximal end of deliverycatheter 20 to deliver electrical signals to and receive signals fromthe telemetry coupling member 22. The electrical signals delivered totelemetry coupling member 22 may be communicatively coupled to IMD 14,e.g., via any of a number of coupling techniques including, but notlimited to, inductive coupling, conductive coupling, magnetic coupling,electromagnetic coupling, capacitive coupling, radio frequency (RF)coupling, electroacoustic coupling, electro-optical acoustic coupling,optical coupling, mechanical coupling, electrical coupling or the like.

FIG. 3 is a schematic diagram illustrating implantable medical devicedelivery system 8 after IMD 14 is delivered to the target locationwithin a patient 10. In other words, IMD 14 has been released fromdelivery catheter 20. After delivery of IMD 14 to the target locationand expulsion from delivery catheter 20, IMD 14 may communicate withexternal device 25. External device 25 could be embodied as a programmerdevice or patient monitor device. External device 25 may, in someinstances, correspond with external device 18. In other words, the sameexternal device may be utilized to communicate with IMD 14 duringimplantation and after implantation. In other instances, external device25 may be a different device.

External device 25 may allow a user, e.g., physician, clinician, nurse,technician or patient, to configure a therapy delivered by IMD 14 or toretrieve data sensed by IMD 14. External device 25 may include a userinterface that receives input from the user and/or displays data to theuser. External device 25 may be a dedicated hardware device withdedicated software for communicating with IMD 14. Alternatively,external device 25 may be an off-the-shelf computing device running anapplication that enables external device 25 to communicate with IMD 14.In some examples, external device 25 may be a handheld computing devicethat may be attached to or otherwise carried by patient 10.Alternatively, external device 25 may be a computer workstation, such asa CareLink® monitor, available from Medtronic, Inc. of Minneapolis,Minn.

IMD 14 may communicate with external device 18 and external device 25 byany of a number of wired and wireless communication techniques. As willbe described in further detail herein, the communication techniquesbetween IMD 14 and external device 18 during implantation may bedifferent than the communication technique used to communicate betweenIMD 14 and external device 25 after implantation. In other instances,the communication technique between IMD 14 and external device 18 duringimplantation may be the same as the communication technique used onceIMD 14 has been implanted, but with different amounts of powerconsumption. IMD 14 may also communicate with a second IMD 24 or otherIMDs in addition to or instead of with external device 25, as shown inFIG. 4. Communication between IMD 14 and IMD 24 may use the samecommunication techniques as used between IMD 14 and external device 18or different communication techniques.

Due to the small size of leadless IMDs, conservation of the energywithin the power source of IMD 14 is desirable. Providing telemetrycoupling member 22 (FIG. 1) within delivery catheter 20 allows powersource energy to be conserved by a variety of methods, includingdelaying use of the IMD telemetry until IMD 14 has been implanted orusing it in a low power mode until implantation is complete.Additionally, delivery catheter 20 eliminates the need to place atelemetry device in a sterile field and ensures the telemetry isreliably coupled to an external device, e.g., external device 25.

FIG. 5 is a schematic diagram illustrating an example delivery catheter30 having an antenna 32 as the telemetry coupling member. Deliverycatheter 30 may correspond with delivery catheter 20 of FIGS. 1, 3 and 4with antenna 32 corresponding to telemetry coupling member 22. Externaldevice 18 is connected to feed line 16 of delivery catheter 30 and sendsor receives electrical signals along feed line 16 to or from antenna 32.In the example illustrated in FIG. 5, the feed line 16 comprises aconductor 34 that extends along a length of catheter body 31 from theproximal end of catheter body 31 to the distal end of catheter body 31adjacent to IMD 36. Conductor 34 is located within an inner lumendefined by catheter body 31. A first portion of conductor 34 forms feedline 16 and a second portion of conductor 34 forms antenna 32. Forexample, the conductor extends from the proximal end of catheter body 31to the distal end of catheter body adjacent to IMD 36, forms antenna 32near the distal end of catheter body 31 and then returns back to theproximal end of catheter body 31.

In the example illustrated in FIG. 5, conductor 34 is connected toexternal device 18 at a proximal end of catheter body 31. Conductor 34forms a coil antenna near the distal end of catheter body 31, whichfunctions as the telemetry coupling member 22. In particular, conductor34 includes one or more turns around a longitudinal axis 38 of deliverycatheter 30. The electrical signal sent from telemetry device 18 causesantenna 32 to create an electromagnetic field for coupling to acorresponding antenna (not shown in FIG. 5) within IMD 36. Conductor 34is exemplary illustrated as feed line 16 and antenna 32 forms a coilantenna in the example of FIG. 5. The conductor may form antennas of anyof a variety of different shapes, such as a planar shape (FIG. 8), acylindrical shape (FIG. 7) or other shape. Moreover, in other instances,feed line 16 and the antenna 32 may be formed from separate conductorsand coupled together, e.g., via an electrical connection.

FIGS. 6, 7 and 8 illustrate further examples of delivery catheters withantennas as telemetry coupling members. FIG. 6 illustrates a distal endof a delivery catheter 40 that includes a feed line 16 and antenna 32which are both contained within the walls of catheter body 41. Antenna32 of FIG. 6 includes one or more turns around a longitudinal axis 38 ofdelivery catheter 40. The turns of antenna 32 are within the walls ofcatheter body 41. In other words, the turns of antenna 32 follow thecircumference of catheter body 41. The turns of antenna 32 may at leastpartially encircle and, in some instances, completely encircle IMD 36when IMD 36 is located in the distal portion of catheter 40.Construction in this manner allows for a large volume within which theelectromagnetic field is sufficient for communicating with IMD 36. Assuch, the placement of the corresponding antenna within IMD 36 is lesscritical when the delivery catheter antenna surrounds IMD 36 than in theembodiment in which the delivery catheter antenna is located near oneend of IMD 36. Moreover, embedding feed line 16 and antenna 32 in thewalls of catheter body 41 may simplify the process for IMD 36 to bedelivered from outside patient 10 to inside patient 10 through deliverycatheter 40 after delivery catheter 40 is placed at least partiallywithin patient 10. Without the feed line 16 embedded within the walls ofcatheter body 41, to deliver the IMD 36 from outside the patient 10 toinside the patient 10, requires inserting the telemetry coupling memberafter inserting the IMD 36 and moving both from the proximal end ofdelivery catheter to the distal end of delivery catheter.

Although feed line 16 and antenna 32 are illustrated in FIG. 6 as beingcontained within the catheter body 41, in other instances feed line 16and/or a portion of antenna 32 may be located within the inner lumendefined by the walls of the catheter body. For example, feed line 16 maybe located within the inner lumen defined by the walls of the catheterbody and may couple to antenna 32 which may be located within the wallsof the catheter body or vice versa.

FIG. 7 illustrates a distal end of another example delivery catheter 44in which antenna 32 encircles at least a portion of IMD 36 at or nearthe distal end of delivery catheter 44. In the example of FIG. 7, feedline 16 and antenna 32 are within the lumen of delivery catheter 44(similar to the embodiment of FIG. 5), but antenna 32 encircles at leasta portion of IMD 36 and, in some instances, completely encircles IMD 36.

FIG. 8 illustrates a distal end of another example delivery catheter 46that includes an antenna 48 which forms a planar surface. The planarsurface formed by antenna 48 is normal to the longitudinal axis 38 ofdelivery catheter 46 and antenna 48 is adjacent to IMD 36, similar toantenna 32 of catheter 30 of FIG. 5.

FIG. 9 is a conceptual diagram illustrating a distal end of an exampledelivery catheter 50 in further detail. Delivery catheter 50 maycorrespond with any one of delivery catheters 20, 30, 40, 44 or 46 orother delivery catheter. Delivery catheter 50 includes a delivery module52 to deliver an IMD 54 to the target location within patient 10. In theexample illustrated in FIG. 9, delivery module 52 of delivery catheter50 contains a telemetry coupling member 22 and is connected to feed line16. Feed line 16 may be a wire or pair of wires used for thebi-directional transmission of signals between external device 18 andIMD 54. However, the transmission may also be unidirectional, eitherfrom external device 18 to IMD 54 or from IMD 54 to telemetry device 18.

IMD 54 is shown conceptually in the right hand portion of FIG. 9. IMD 54may correspond to either IMD 14 or 36, or other IMD described herein.IMD 54 includes an IMD telemetry coupling member 56, circuit 58, powersource 60 and electrode 62. IMD telemetry coupling member 56 may besimilar to telemetry coupling member 22 of delivery catheter 20, e.g.,an antenna, a transducer, an electrical contact, a capacitive plate, anelectrode or the like. IMD telemetry coupling member 56 is locatedadjacent to the delivery module 52 in the illustrated example. Ininstances in which telemetry coupling members 22 and 56 are antennas,the antennas may be formed in a similar manner, e.g., from a coil withone or more turns around a longitudinal axis 38 of delivery catheter 50,or may be formed in different manners. IMD telemetry coupling member 56and telemetry coupling member 22 of delivery module 52 are arranged withrespect to one another in a manner to provide an effective communicativecoupling, e.g., electromagnetic, inductive, RF coupling or the like. Inone example, IMD telemetry coupling member 56 is an antenna wound aroundthe longitudinal axis of delivery catheter 50 or has windings with otherorientations to facilitate construction or communications with otherdevices or for other reasons.

IMD telemetry coupling member 56 connects to circuit 58. Circuit 58 mayinclude functional electronics (modules and/or components) for thefunctions performed by IMD 54, including sensing, therapy, telemetry,programming, testing, measuring, battery monitoring or the like. Powersource 60 connects to circuit 58 to provide power during the servicelife of IMD 54. Power source 58 may, for example, comprise arechargeable or non-rechargeable battery.

IMD 54 includes a capsule 68 and an electrode 62. IMD 54 is implantedsuch that electrode 62 is lodged within viable tissue of the targetlocation for the purposes of stimulating the tissue, sensing a parameterfrom the tissue and in some embodiments, conductively coupling to thetissue for the telemetry communication. In the example illustrated inFIG. 9, IMD 54 is a capsule 68 of cylindrical shape. However, thetechniques of this disclosure are not limited to cylindrical shapes.Capsule 68 may, in other instances, take on any of a variety of shapes.Capsule 68 is built to fit within the lumen of delivery catheter 50 andaccommodate battery 60 or components/circuits to harvest power frominternal or external sources, circuit 58, and IMD telemetry couplingmember 56. While capsule 68 is long enough to encapsulate theaforementioned components, capsule 68 is not so long as to inhibitmovement through the delivery catheter 50, especially if deliverycatheter 50 is to be placed before IMD 54 is received into deliverycatheter 50. The length of the capsule 68 may be limited to accommodatedelivery through the path taken by the delivery catheter 50 to reach thetarget implantation site. The dimensions of capsule 68 may also belimited by the size and structures of the target organ.

Electrode 62 extends from capsule 68 to deliver therapy to, to sense aparameter from the target location and, in some embodiments, toconductively couple to a tissue for the telemetry communication.Electrode 62 may be lodged within a tissue at the target location orlocated adjacent to the target location. In the case of an implantablepacemaker, for example, electrode 62 may be lodged within tissue of aheart chamber to deliver pacing pulses to the chamber of the heart orsense depolarizations of the chamber of the heart. IMD 54 of FIG. 9 isillustrated for exemplary purposes and should not be considered limitingof the techniques as described herein. In other examples, electrode 62may not extend from capsule 68. Instead or in addition, some or theentire exterior of capsule 68 may be formed from a conductive materialthat may function as the electrode. In further examples, IMD 54 mayinclude more than one electrode. In other instances, IMD 54 may notprovide electrical stimulation therapy and, therefore, not include anelectrode at all. Instead, IMD 54 may include some other type of sensor,such as a glucose sensor, pH sensor, pressure sensor, accelerometer, orany other sensor, to measure a parameter of patient 10.

IMD 54 may further include a fixation mechanism (not shown) to affix IMD54 to the target location. The fixation mechanism may include suturesthat are sutured to the target location, flexible tines that protrudeinto the target location, helical mechanisms that are screwed into thetarget location, a stent for retention in a vessel or the like. In someinstances, at least a portion of electrode 62 may be shaped to form thefixation mechanism. In other words, electrode 62 is the fixationmechanism. For example, at least a portion of electrode 62 may be shapedinto a helical structure to screw into the target location to affix IMD54 as well as deliver therapy to or sense a parameter of the targetlocation. As described above, delivery catheter 50 may include one ormore pull wires or other means for manipulating the position of IMD 54to move IMD 54 within catheter body or to affix (e.g., via turning) IMD54 to the target location.

The delivery catheter 50 may also include an attachment mechanism fordetachably coupling to IMD 54. The attachment mechanism may be used topush, pull, rotate or otherwise manipulate the position of IMD 54 withindelivery catheter 50. As one example, the attachment mechanism may beused to push IMD 54 to the distal end of delivery catheter 50, rotateIMD 54 to affix IMD 54 to the target location and then release IMD 54from delivery catheter 50. In this manner, IMD 54 is expelled throughthe distal end of delivery catheter 50 and placed within the targetlocation. In the example illustrated in FIG. 9, feed line 16 may alsofunction as the mechanism to manipulate the position of IMD 54, e.g.,using delivery module 52, in addition to functioning as the feed line.

Prior to expulsion of IMD 54 from delivery catheter 50, it may bedesirable to determine whether IMD 54 is located in a suitable locationsuch that IMD 54 will function as desired or intended and is notdetrimental to the function of the target organ or other location. Assuch, it may be desirable to perform one or more tests prior toexpulsion of IMD 54 from delivery catheter 50 to ensure these functionalexpectations will be met during the service life of IMD 54 or to gainconfidence that IMD 54 will remain in the desired position. In theexample of the IMD as a cardiac pacemaker system, it may be desirable tomeasure the performance of electrode 62. Such testing might includemeasurement of the stimulation threshold, the impedance of theelectrode-tissue interface as presented to IMD 54, the amplitude ofsensed electrogram potentials from appropriate chambers of the heart,the amplitude of sensed electrogram potentials from other chambers ofthe heart, the appropriate detection of various physiologic sensorswithin IMD 54, the hemodynamic consequences of pacing (e.g. cardiacoutput when paced from the selected location), the communicativecoupling to IMD 54 or between IMD 54 and other devices implanted or tobe implanted within the patient, any hemodynamic obstruction that may becaused by the IMD 54 as located in the heart, and the security of thefixation (e.g., applying tension to the IMD to determine whether thefixation mechanism has sufficiently engaged the appropriate surroundingtissue).

IMD 54 may perform the one or more tests in response to a communicationsignal from external device 18. In this manner, external device 18controls IMD 54 to perform the one or more tests. After performing theone or more tests, IMD 54 sends a communication signal back to externaldevice 18 that includes the results of the performed tests. The resultsprovided to external device 18 may be raw sensor data that may beprocessed by external device 18 to determine the suitability ofattachment of IMD 54 to the target location. Alternatively, IMD 54 mayprocess the data and provide an indication of the suitability of theattachment of IMD 54 to the target location via the communicationsignal. External device 18 may present the results to a user via displaymodule 29 or other output.

FIG. 10 a is a schematic diagram illustrating an example deliverycatheter 70 that includes electrical connectors 72, 74 that connectdirectly to IMD 76. Catheter 70 may correspond with catheter 20 of FIGS.1, 3 and 4 and IMD 76 may correspond with IMD 14. The telemetry couplingmember of delivery catheter 70 comprises electrical connectors 72, 74and the communicative coupling is an electrical coupling. Electricalconnections 72, 74 allow signals from telemetry device 18 to flowdirectly to the telemetry circuitry within IMD 76. By virtue of using adirect electrical connection for the telemetry of information betweenexternal device 18 and IMD 76, communication is extremely reliable,noise-free and may require less energy as compared to wireless methods.When IMD 76 has been navigated to an appropriate position, fixed to thetarget location and expelled from delivery catheter 70, IMD 76 isdisconnected from the feed line 16 and communicates with external device25 (see FIG. 3) via wireless communication.

FIG. 10 b provides an example detail view of IMD 76 with detachableelectrical connectors 73, 75. Electrical conductors may be routed thoughinsulative structures in the housing of IMD 76 to form electricalconnectors 73 and 75. The electrical conductors extending throughinsulative structures in the housing of IMD 76 may electrically coupleto one or more components within IMD 76, such as a power source (FIG. 9reference numeral 60, FIG. 21 reference number 144) or circuitry (e.g.,a telemetry module) within IMD 76. Connector mechanisms may be providedto detachably connect feed line 16 to IMD 76 and then disconnect priorto delivery of IMD 76 to the target location. In other words, theconnector mechanisms connect electrical connects 73, 75 to electricalconnectors 72, 74. Besides the communicative coupling mechanism, IMD 76functions in a similar manner to IMDs 14, 36 to provide therapy toand/or monitor a parameter of patient 10.

FIG. 11 a is a schematic diagram illustrating an example deliverycatheter 80 that includes capacitive plates 82, 84 that communicativelycouple to IMD 86. Catheter 70 may correspond with catheter 20 of FIGS.1, 3 and 4. The telemetry coupling member of delivery catheter 80comprises capacitive plates 82, 84 and the communicative coupling is acapacitive coupling. Capacitive plates 82, 84 are located at the distalend of feed line 16 and align with the complementary IMD plates 88, 89(FIG. 11 b) on IMD 86.

Capacitive plate 82 and IMD plate 88 are parallel plates or nearlyparallel plates with blood or other body fluid as a dielectric. In thisconfiguration plate 82 and plate 88 form a capacitor. Similarly,capacitive plate 84 and the IMD plate 89 form another capacitor. Throughthese capacitive connections, telemetry device 18 and IMD 86 exchangetelemetry signals without direct electrical connection. Besides thecommunicative coupling mechanism, IMD 86 functions in a similar mannerto IMDs 14, 36 to provide therapy to and/or monitor a parameter ofpatient 10.

FIG. 12 is a schematic diagram illustrating an example delivery catheter90 that includes a transducer 92 that communicatively couples to IMD 94.Catheter 90 may correspond with catheter 20 of FIGS. 1, 3 and 4. Thetelemetry coupling member of delivery catheter 90 is transducer 92 andthe communicative coupling is a mechanical, electromechanical, acoustic,electroacoustic, optical or electro-optic coupling. At the distal end offeed line 16, an electrical connection from feed line 16 is made totransducer 92. Transducer 92 converts electrical signals from the feedline to nonelectrical signals. The nonelectrical signals may, forexample, be vibration, sound or other nonelectrical signal. Themechanical connection between delivery system transducer 92 and acorresponding transducer within IMD 94 is maintained either throughdirect mechanical contact, mechanical linkage, through contact withdelivery catheter 90 or through fluidic means such as through blood,other body fluid, saline or the like. The corresponding transducer (notshown) is located within IMD 94 to receive and send the communicationfrom IMD 94. Besides the communicative coupling mechanism, IMD 90functions in a similar manner to IMDs 14, 36 to provide therapy toand/or monitor a parameter of patient 10.

FIG. 13 is a schematic diagram of a delivery catheter 100 coupled toexternal device 18. External device 18 incorporates analyzer module 27(see FIG. 2) to test the suitability of IMD 104 to perform its desiredfunctions. Analyzer module 27, however, may be constructed as a standalone instrument or in combination with other external instrumentationsuch as external device 18, a programming device, a physiologicmonitoring system, an imaging system or a navigation system. Deliverycatheter 100 includes conductors 106 and 108 that serve to connectexternal device 18 to one or more electrodes of IMD 104. In other words,conductors 106 and 108 may be viewed as control lines or feed lines thatcarry electrode signals to and from electrode 110, e.g., for testing thesuitability of the implant location. Conductors 106 and 108 may also beemployed to translate mechanical forces from the proximal end to thedistal end of the delivery catheter for use in moving or manipulatingthe position of IMD 104, in addition to serving in electrical roles suchas to carry telemetry signals to and from the IMD and/or to carrysignals to and from an electrode 110. In the example illustrated in FIG.13, conductor 106 detachably connects external device 18 to electrode110 of IMD 104 through the electrode connection 114 and conductor 108detachably connects external device 18 to a capsule 112 of IMD 104 viacapsule connection 116.

Capsule 112 of IMD 104 may be made from a conductive material, such asof titanium, or from a non-conductive material, such as ceramic. In theexample of a conductive capsule, the connection from the electroniccircuitry inside capsule 112 to electrode 110 comprises an insulator anda seal such that a central conductor passes through capsule 112 of IMD104 while being electrically insulated from capsule 112. Capsule 112, ifconductive, may be used as another electrode, either using the whole ofcapsule 112 or in part. To be used in part, capsule 112 may be coated,in part, with an insulative coating such as paralyene, the remaininguncoated portion serving as the another electrode. In the example of aninsulative capsule, the connection to electrode 110 comprises a sealsuch that the central conductor passes through capsule 112 of IMD 104but further insulation may not be necessary. In both examples,mechanical support such as strain relief may be integrated into theseal.

External device 18 may test the electrical suitability of capsule 112and electrode 110 of IMD 104 to perform the necessary functions of IMD104. In the example of a cardiac rhythm management device, thesefunctions may include stimulating the heart, sensing depolarizations ofthe heart, presenting a suitable impedance to IMD 104 and telemetrycommunication. Other functions may be tested for other types of IMDs,e.g. neurostimulators, drug pumps or the like, in addition to or insteadof the functions described above. After testing the suitability of IMD104 to perform its desired function, conductors 106 and 108 can bedisconnected or detached from the respective connections 114 and 116 toenable IMD 104 to be released from delivery catheter 100. Additionally,IMD 104 may be turned on or powered up in response to the testingindicating desired functionality. Power is conserved by having externaldevice 18 perform the suitability testing instead of IMD 104.

The position and orientation of an electrode or electrodes on an IMD maybe important for embodiments utilizing conductively coupledcommunication through the body as the communication signal generated bythe IMD may be weak. Little power can be budgeted for telemetrycommunication as the power source within the IMD must be small to fitwithin the IMD and to power the circuitry for its therapeutic,monitoring and telemetric communication purposes for a reasonableservice life. Delivery by catheter enables placement of the IMD deepwithin the body. For large patients and especially for obese patients,the depth of IMD placement may result in a long distance between thebody electrodes on the surface of the patient and the electrodes usedfor telemetry on the IMD. This long distance may result in especiallysmall signals on the body surface. Clinical follow-up and care ofpatients with IMD's generally follows a standard practice such asaffixing electrodes to the patient for monitoring during such sessions.Such procedures demand to be done in a minimum of time with little to noexperimentation in the setup of the system. Therefore, it is desired thebody electrodes be affixed to the patient in a standard position such ason the patient's wrists, on the patient's chest or some familiaranatomical location. Locations that can be accessed without the need forthe patient to disrobe are, further, preferred. With a fixed andstandard location for body electrodes for telemetric communication withthe IMD, some positions and associated orientations of the IMD may workbetter than others.

FIG. 14 is a schematic diagram of a delivery catheter 120 whichcommunicates using conductive coupling. Delivery catheter 120 includes afeed line 16 coupled to telemetry coupling electrodes 122, 124 on (e.g.,at or near) the distal end of catheter 120. External device 18 iscoupled to the feed line 16 at the proximal end of catheter 120.External device 18 generates and receives a communication signal throughthe telemetry coupling electrodes 122, 124 which are inside the body ofpatient 10 using the body as a conductor, a process sometimes referredto as tissue conductance communication (TCC). Such a communicationtechnique is described in detail in U.S. Pat. No. 4,987,897 to Funkeentitled, “BODY BUS MEDICAL DEVICE COMMUNICATION SYSTEM” filed Sep. 18,1989, which is incorporated by reference herein in its entirety.

Telemetry coupling electrodes 122, 124 may be placed on catheter 120 toapproximate the spacing of telemetry electrodes on IMD 126. In thismanner, testing conductively coupled communication with telemetrycoupling electrodes 122, 124 will mimic the telemetry electrodes on IMD126. For example, IMD 126 may include telemetry electrodes on oppositeends of IMD 126 (e.g., a proximal and distal end of IMD 126corresponding to the proximal and distal references of catheter 120while IMD 126 is resident in catheter 120) and telemetry couplingelectrode 122 may be located at the distal end of catheter 120 toapproximate an electrode at the distal end of IMD 126 and telemetrycoupling electrode 124 may be located slightly proximal from the distalend of the catheter body to approximate an electrode located at theproximal end of IMD 126. Other configurations of telemetry couplingelectrodes 122, 124 may be utilized to approximate the location oftelemetry coupling electrodes of IMD 126. In this manner, telemetrycoupling electrodes may provide an accurate indication as to telemetryperformance after IMD 126 is implanted.

Telemetry coupling electrodes 122, 124 may take on a variety of shapesand sizes such as a ring or a band around the circumference of elongatecatheter 120 or they could be other shapes which do not encircle thecatheter. The telemetry coupling electrodes 122, 124 could extendthrough the wall of catheter 120 to provide contact with blood or bodyfluid or saline or the like within catheter 120 as well as being exposedto blood or body fluid on the outside of catheter 120.

FIG. 14 a is a schematic diagram of a delivery catheter 156 whichcommunicates using conductive coupling. Delivery catheter 156substantially conforms to delivery catheter 120 of FIG. 14, but deliverycatheter 156 incorporates one or more holes in the catheter wall toallow the ingress of blood and conductively coupled communicationbetween IMD 126 and a body electrode (described below). In other words,the delivery catheter body may be formed in such a manner as to createthe voids or holes. The holes in delivery catheter 156 are placed so asto provide electrical coupling through the ingress of blood to thecentral lumen of catheter 156 and to retain the strength andmaneuverability necessary for navigation and delivery of IMD 126 withinthe patient 10.

While FIG. 14 a illustrates the holes in catheter 156 as extending fromthe proximal end to the distal end, the holes may be placed only incertain portions of catheter 156. For example, the holes might be placedonly in the distal portion of catheter 156 such that they expose IMD 126to the blood when IMD 126 is placed in the distal portion of catheter156 for navigation, testing and delivery. In another embodiment, thehole placement includes the use of holes only in the distal portion ofcatheter 156 and only in the area around a proximal telemetry electrode(not shown) on IMD 126 where the proximal telemetry electrode may be adistinct telemetry electrode member or may be an uninsulated portion ofthe capsule. In yet another embodiment, holes may extend along thelength of catheter 156 that will indwell within patient 10. That is, theholes would extend from the site 12 of entry into patient 10 to thedistal end of catheter 156 so conductive communication with IMD 126could be established as IMD 126 is passed through catheter 156 during aprocedure in which catheter 156 is first introduced into patient 10 andthen IMD 126 is placed in the distal end of catheter 156.

FIG. 15 illustrates the delivery system of FIG. 14 indwelling in patient10. The external device 18 is coupled to body electrodes 172, 174 viabody electrode cables 176, 178. The external device 18 assesses thecommunication between the indwelling electrodes 122, 124 and electrodeswhich are on the body surface, body electrodes 172, 174 in the exampleillustrated in FIG. 15 using conductive coupling (e.g., TCC). Theexternal device 18 may communicate with the IMD 126 by use of thetelemetry coupling electrodes 122, 124. For example, telemetry couplingelectrodes 122, 124, which are electrically coupled to external device18, may be conductively coupled to corresponding electrodes (not shownin FIG. 15) on IMD 126. Further, the external device 18 may direct theIMD 126 to communicate with the body electrodes 172, 174 via conductivecoupling.

To assess the communication, the external device 18 may transmit acommunication signal from the body electrodes 172, 174 and measure thereceived communication signal at the IMD 126 and/or the telemetrycoupling electrodes 122, 124. The communication may also be in theopposite direction. The IMD 126 may transmit a communication signal andthe external device may then receive the signal from the body electrodes172, 174. In a third mode of communication, the external device 18transmits a communication signal from the telemetry coupling electrodes122, 124 and the signal is then received by the body electrodes 172,174.

The IMD 126 or the external device 18 may measure the quality of thecommunication signal to assess the viability of communication betweenthe IMD 126 and the body electrodes 172, 174. In the communicationassessments in which IMD 126 is involved (e.g., either as thetransmitting or receiving device), the quality of the communicationbetween IMD 126 and the body electrodes 172, 174 is directly determined.In the communication assessments in which IMD 126 is not involved (e.g.,the signals are transmitted between body electrodes 172, 174 andtelemetry coupling electrodes 122, 124), the quality of thecommunication signal between IMD 126 and the body electrodes 172, 174 isbeing approximated since the location of telemetry coupling electrodes122, 124 are located in close proximity to the eventual positionfollowing implantation of the electrodes on IMD 126 that will be usedfor communication. The quality of the communication signal may beassessed by a variety of methods including but not limited to atransmission power required for signal detection, a received signalstrength, a received signal to noise ratio, a bit error rate, a datathroughput rate, a data dropout rate, a background noise floor, anoptimum frequency, an optimum set of electrodes in IMD 126, or acombination of these measurements. The IMD 126 and the external device18 may communicate and select from a variety of appropriatecommunication frequencies. Certain communication frequencies may beselected to avoid interfering signals from other devices such as otherIMDs or the like. The IMD 126 and the external device 18 may synchronizethe sequential testing of the variety of communication frequencies andthen select the communication frequency which is determined to beoptimal for reliable communication. The IMD 126 may incorporate a seriesof electrodes (not shown) from which the IMD 126 may select or bedirected by external device 18 to select the electrodes for telemetrycommunication. The IMD 126 can sequentially select from among the seriesof electrodes to test and select the electrode which is determined to beoptimal for reliable communication. The communication signal paththrough the body may be assumed to be the same in both directions soonly one direction need be tested or it may be tested in bothdirections.

The external device 18 reports the communication signal quality in anelectronic format, in a printed format, or by visual display via thedisplay module 29. The report contains any of the measurements of thecommunication signal quality and may contain these measurements as afunction of time. The various measurements may be combined into asimplified quantitative index of the communication signal quality so theuser need not be concerned with the technical details of thecommunication but only with whether the communication signal quality issatisfactory for long-term use with IMD 126.

Assessment of the communication signal quality is useful to guideplacement of the IMD 126. If, once implanted, as illustrated in FIG. 16,the IMD 126 placement is not expected to result in reliable and usefulcommunication between the IMD 126 and the external device 18,implantation may be ill-advised for lack of communication could renderthe device not useful or might require subsequent extraction. If the IMD126 is placed in position for implantation but still within and/orattached to the delivery catheter, the communication signal quality canbe tested. Referring back to FIG. 15, the external device 18 utilizesthe communication signal quality measurements to predict whether thecommunication between the IMD 126 and the external device 18 will besuccessful after the implantation assuming the orientation and positionof the IMD 126 are not substantially changed from the position duringwhich testing of the communication signal quality is performed. The IMD126 may be placed such that the electrode on the IMD 126 which may beused for therapeutic or monitoring purposes but is also used forconductively coupled communication through the body is essentially fullylodged and implanted but not detached from the delivery system. In thisposition, testing the communication signal quality between the telemetryelectrodes of IMD 126 or telemetry coupling electrodes 122, 124 and thebody electrodes 172, 174 provides the external device 18 sufficientinformation for the external device 18 to predict whether communicationbetween the IMD 126, after implantation, and the external device 18 willbe satisfactory.

Various embodiments may be combined in the IMD delivery system. FIG. 17illustrates an embodiment wherein the delivery system catheter comprisesboth telemetry coupling electrodes 122, 124 and telemetry couplingmember 22. In this embodiment, telemetry signal communication with IMD132 may be accomplished by the various methods attributed above to thetelemetry coupling member as well as the conductive coupling usingtelemetry coupling electrodes 122, 124. IMD 132 may correspond to IMD126 of FIGS. 14, 15 and 16. Further, the telemetry coupling electrodes122, 124 have utility in determining the orientation and position of thedistal catheter end as described below.

Referring back to FIG. 16, if the communication signal quality betweenthe body electrodes 172, 174 and the IMD 126 is weak or is reported tobe unsatisfactory, an alternative for the medical procedure is toreposition the body electrodes 172, 174. The communication signalingwith the IMD 126 may be successful with a special position of the bodyelectrodes 172, 174. As the IMD 126 is small, the distance betweenelectrodes on the IMD 126 which are used for conductively coupledcommunication must, by necessity, also be small. Consequently, thedipole used for generation and reception of conductively coupledcommunications signals will be small and directional. By attaching aplurality of electrodes 180, 182, 184, 186, 188, 190 to the body (seeFIG. 18) and measuring the communication signal quality with each of theelectrodes, a variety of body electrode positions can be evaluated sothe external device 18 can then report the results. The plurality ofelectrodes 180, 182, 184, 186, 188, 190 may be coupled to externaldevice 18 via cables 240, 242, 244, 246, 248, 250, respectively.Further, the external device 18 can then recommend a position for thebody electrodes 172, 174 (see FIG. 17) for successful communicationbetween the body electrodes 172, 174 and the IMD 126 (FIG. 17).

The above describes finding suitable positions for the body electrodesgiven the IMD has or will be implanted in a certain position andorientation. An alternative method provides the user with performancemeasures as a function of various positions and orientations of the IMD.As the user manipulates the delivery system catheter 130 to explorepossible implantation sites, the external device 18 records and thenreports communication performance as a function of potential IMD siteand orientation. The position and orientation for implantation may bedetermined by various methods. Some example methods for determiningposition and orientation information are described in U.S. Pat. No.5,697,377, to Wittkampf entitled, “CATHETER MAPPING SYSTEM AND METHOD,”which was filed Nov. 22, 1995 and U.S. Pat. No. 5,983,126 to Wittkampfentitled, “CATHETER LOCATION SYSTEM AND METHOD,” which was filed Aug. 1,1997, both of which are incorporated herein by reference in theirentirety. These methods include a three-dimensional measurement ofpositions within a patient, comprising applying respectivethree-dimensional orthogonal alternating current signals at respectivedifferent frequencies, corresponding substantially to x, y and zdirections through said patient, inserting a catheter into said patient,said catheter having a mapping electrode and at least one otherelectrode and outputting position data representative of such obtainedthree-dimensional x, y, and z positions. However, other techniques fordetermining position and orientation for implantation may also be used.

The plurality of electrodes 180, 182, 184, 186, 188, 190 may be utilizedfor catheter location mapping as with the LOCALISA™ intracardiactracking system sold by Medtronic, Inc. having a place of business inMinneapolis, Minn. Such a system can localize the position andorientation of the telemetry coupling electrodes 122, 124 on thedelivery system catheter 130 or the telemetry electrodes of IMD 132.Alternative localization techniques may be used includingelectromagnetic localization such as the AXIEM™ electromagnetic trackingsystem sold by Medtronic Navigation, Inc. having a place of business inLouisville, Colo. An electromagnetic tracking system can localizesensors in the indwelling objects yielding position and orientation ofthe delivery system catheter 130 and, therefore, the telemetry couplingelectrodes 122, 124 and the IMD 132 while coupled to the delivery systemcatheter 130. The position sensor may be located on (e.g., at or near adistal end) of the catheter 130.

The plurality of electrodes 180, 182, 184, 186, 188, and 190 are used totest the communication signal quality with IMD 132 or telemetry couplingelectrodes 122, 124. The external device 18 may measure the signalquality between telemetry coupling electrodes 122, 124 or telemetryelectrodes of IMD 132 and each of the electrodes 180, 182, 184, 186,188, and 190 and determine which is best. Further, the external device18 may interpolate the measurements of the communication signal qualityfrom the various electrodes to predict intermediate locations betweenthe body electrodes 180, 182, 184, 186, 188, and 190 where thecommunication signal quality will likely provide the best communicationbetween the IMD 132 and a body electrode. The plurality of electrodesillustrated in FIG. 18 is used for the localization described aboveusing the LocaLisa™ and also for the assessment of communication signalquality. For localization systems such as the Axiem™ system, describedabove, the body electrodes do not serve for the localization and,therefore, need not be positioned for such purposes. When used with theAxiem™ system, the body electrodes may be placed in other locations (notshown) on the patient. In this example, the number and placement of bodyelectrodes may be planned solely for the purpose of assessingcommunication signal quality. Understanding the IMD telemetry electrodeorientation aids in predicting the area on the body where the bestcommunication signal is expected as the maximum signal would occur alonga vector which is normal to the unit vector between the two telemetrycommunication electrodes on the IMD 132. Upon predicting an intermediatelocation where the communication will be best, the external device 18recommends a location for the placement of body electrodes 172, 174 (seeFIG. 17) for subsequent follow-up procedures with the specific patient.Notation can be made in the patient's medical chart and the patient 10informed as to the location required for the body electrode forsuccessful communication with the IMD 132. The patient then remindsmedical personnel, if the need arises, as to the location for telemetrywith their IMD. If the IMD functions well in a particular location withrespect to the therapeutic and monitoring clinical goals, the IMD isthen implanted in the particular location and, if the particularlocation does not have other adverse consequences on the well being ofthe patient, requiring a special position for the communication with theIMD is a decision that may be made by the user.

The telemetry coupling electrodes 122, 124 on the distal end of thedelivery system catheter may be used with the localization system tovisualize the position and orientation of the telemetry couplingelectrodes 122, 124. With this information, the user manipulates thedelivery system catheter 130 while the external device 18 reports thecommunication signal quality. The external device 18 then develops areport and display of the communication signal quality as a function ofthe position of the distal portion of the delivery system catheter 130.In other words, the external device 18 may map the communication signalquality over the extent of the exploration. This report may aid inguiding the user to suitable locations for implantation of the IMD 132.The user then selects a site for permanent implantation. Duringmanipulation of the delivery system catheter 23, the localization module28 in the external device 18 provides guidance towards the selectedsite. For example, localization module 38 may display athree-dimensional view of the localization to provide visual cues as todistance and direction the distal end of the catheter 23 must bemanipulated in order to move the delivery system catheter 23 and the IMD132 to achieve the specific site and orientation of the IMD 132 forpermanent implantation. In this manner, mapping the communication signalquality over the extent of the exploration by the user can be recordedand useful in the selection of a site for permanent implantation.

FIG. 19 is a block diagram illustrating an example IMD 120 in furtherdetail. IMD 120 includes a capsule 127 that houses the components of IMD120 and an electrode 129 extending from capsule 127 via feed through128. IMD 120 may correspond to any of IMDs 14, 36, 54, 76, 86, 94, or104. Feed through 128 includes a conductor to connect to electrode 129and insulate it from capsule 127 surrounding IMD 120. As describedabove, electrode 129 is placed within or adjacent to the targetlocation, e.g., tissue, nerve, muscle or organ, of patient 10.

IMD 120 of FIG. 19 includes an electrode switch 133, a therapy module134, a sensing module 136, a memory 138, a processor 140, a telemetrymodule 142, a telemetry coupling member 148, a power source 144 and apower switch 146 within capsule 127. The various components of IMD 120are interconnected via one or more data buses or direct connections. IMD120 may include more or fewer components than illustrated in FIG. 19depending on the functionality provided by IMD 120. For example, IMD 120may not include therapy module 134 in instances in which IMD 120 isdesigned for sensing or monitoring purposes only, such as an implantableloop recorder.

IMD 120 is configurable to operate in a number of different power states(shown in Table 1, below). IMD 120 uses a different amount of power ineach of the power states. IMD 120 may operate in a first power state,referred to herein as a “ship state,” during which no power is providedto any of the components of IMD 120. During the ship state, power switch146 may be set to a first position to disconnect power source 144 fromthe other components of IMD 120. IMD 120 may be configured in the shipstate during shipping from a manufacturing facility to a clinicalfacility. Power switch 146 operates with a very small current so as tonot degrade the service life of the IMD 120. Components which may beutilized for the switching function within the power switch 146 aretransistors, field effect transistors, MEMS switches or other componentwhich offers low quiescent current drain.

Prior to being implanted, IMD 120 may be configured to operate in asecond power state, referred to herein as an “implant state,” duringwhich power is provided to some or all of the other components of IMD120. During the implant state, power switch 146 is set to a secondposition or state to couple power source 144 to at least some of thecomponents of IMD 120. For example, IMD 120 may be configured from theship power state to the implant power state in response to a telemetrysignal of sufficient strength being received by IMD 120 so the powerharvested by the IMD is sufficient to activate power switch 146.

During the implant state, telemetry module 142 operates in a low powerstate in which a transmitter of telemetry module 142 is set to a lowtransmit power and/or a receiver of telemetry module 142 is set to a lowsensitivity. Telemetry module 142 may operate in this low power stateduring implantation due to the close proximity of telemetry couplingmember 148 of IMD 120 and the telemetry coupling member of the deliverycatheter, e.g., telemetry coupling member 22. In other words, the powerrequired for reliable transmission between telemetry device 18 and IMD120 is low due to the proximity of telemetry coupling member 148 of IMD120 and telemetry coupling member 22 of the delivery catheter. As such,the power drain by telemetry module 142 is reduced as compared to thedrain required for communication from IMD 120 to a device outside thebody, such as external device 24. In this manner, power source 144 maybe conserved with regards to the drain from the use of telemetry. Inother instances, IMD 120 may not be configured into the implant state,but transition right to one of the power states described below.

After navigating IMD 120 to a target tissue location, IMD 120 mayperform one or more tests to verify that IMD 120 functions as desiredprior to releasing IMD 120 from the delivery catheter. For example,processor 140 may control therapy module 134 and sensing module 136 tomeasure a stimulation threshold, an impedance of the electrode-tissueinterface as presented to IMD 120, an amplitude of sensed electrogrampotentials from appropriate chambers of the heart, an amplitude ofsensed electrogram potentials from other chambers of the heart,appropriate detection of various physiologic sensors within the IMD,hemodynamic consequences of pacing (e.g. cardiac output when paced fromthe selected location), any hemodynamic obstruction that may be causedby the IMD 120 as located in the heart.

Processor 140 may, in one instance, perform the one or more tests inresponse to signals or commands received by telemetry module 142 from anexternal device coupled to the delivery catheter in which IMD 120 islocated, such as external device 18. In this case, processor 140 maycontrol telemetry module 142 to transmit the results of the tests to theexternal device coupled to the delivery catheter to allow a user toassess the suitability of the implant location. In other instances, IMD120 may not perform the test. Instead, an external device, such asexternal device 18 of FIG. 17 may perform these tests while the deviceoperates in the ship state. In this case, IMD 120 may not operate in theimplant state.

Additionally, IMD 120 may test the communicative coupling to IMD 120 orto other devices implanted or external to the patient. In this case,telemetry module 142 enters a high power state, referred to herein as a“Tele-Hi state.” During the Tele-Hi state, the transmitter of telemetrymodule 142 operates at a higher power relative to the low power stateand the receiver of telemetry module 142 operates at a highersensitivity relative to the low power state to allow communication withexternal device 18 (e.g., external programmer) to be tested and verifiedbefore final release of IMD 120 within the body of patient 10. Telemetrymodule 142 operates in the Tele-Hi power state for this testing becauseof the increased distance from telemetry coupling member 148 of IMD 120and an antenna of external device 18 is considerably further than thedistance between telemetry coupling member 148 of IMD 120 and telemetrycoupling member 22 of the delivery catheter. In other words, the longertelemetry distance requires a higher power for the transmitting and ahigher sensitivity for the receiving in the IMD telemetry module 142.IMD 120 may also use the Tele-Hi power state when a telemetry session isinitiated after implantation within patient 10, e.g., during a follow-upsession.

After testing is performed, IMD 120 transitions to another power statethat will be used during the majority of the service life of IMD 120.This state is referred to herein as the “service state.” During theservice state, telemetry module 142 may operate in a sleep mode orwakeup mode in which the transmitter of telemetry module 142 is turnedOFF and the receiver of telemetry module 142 periodically scans fortelemetry signals destined for IMD 120. By only periodically using thetelemetry receiver function in telemetry module 142 and not using thetelemetry transmit function, telemetry module 142 consumes only a smallamount of power.

Table 1 provides a summary of the example power states of IMD 120. InTable 1, the column titled “circuit power” refers to the state of powerswitch 146, the column titled “Telemetry Transmit” refers to the mode ofthe transmitter of telemetry module 142 and the column titled “TelemetryReceive” refers to the mode of the receiver of telemetry module 142.

TABLE 1 Circuit Telemetry Telemetry State Power Transmit Receive ShipOFF OFF OFF Implant ON Low Power Low Sensitivity Tele-Hi ON High PowerHigh Sensitivity Service ON OFF Periodic

IMD 120 may, in some instances, further include electrode switch 133that electrically couples therapy module 134 and sensing module 136 toelectrode 129 when electrode switch 133 is closed and electricallyisolates therapy module 134 and sensing module 136 from electrode 129when electrode switch 133 is open. In one example, electrode switch 133may be in the open position during the ship state and the implant stateto isolate therapy module 134 and sensing module 136 from the electrode.Electrode switch 133 thus allows the electrical connections of electrode129 to be disconnected during the process of navigating and positioningIMD 120 for implant. In this case, an external connection to electrode129 may be utilized to test the suitability of electrode 129 forstimulating and sensing in the tissue of patient 10.

An external device, such as external device 18 or a device including ananalyzer module, may verify the electrode-tissue properties, thusconserving power resources of IMD 120 that would have been used toperform the suitability testing/verification. Additionally, by removingthe electrical connections to electrode 129 within IMD 120, preciseelectrical measurements of the stimulation threshold, the pacingimpedance of the electrode and electrogram measurements of the slew rateand the amplitude of the tissue depolarizations may be made without theadverse effects of a parallel impedance derived from the circuitrywithin IMD 120. These measurements allow an assessment of electrode 129to ensure the adequate long-term performance and to ensure the electrodeis lodged in viable tissue. After performing the suitability testingusing the external connection, electrode switch 133 may be closed toelectrically connect therapy module 134 and sensing module 136 toelectrode 129.

In other embodiments, however, IMD 120 performs the measurements to testthe suitability of IMD 120 to perform its desired functions at theproposed location of implant. In this example, IMD 120 may not includean electrode switch 133. Instead, the electrode may be directlyconnected to pacing module 134 and sensing module 136 via feed through126 at all times. The measurements performed by IMD 120 may betransmitted to external device 18 or other external device via telemetrycoupling member 148 of the delivery catheter.

Data and control information is exchanged within IMD 120 as shown inFIG. 19 between electrode switch 133, therapy module 134, sensing module136, memory 138, processor 140, telemetry module 142 and power switch146. Memory 138 contains the data used for operating processor 140 andanalyzing the performance of IMD 120. Memory 138 may includecomputer-readable instructions that, when executed by processor 140 orother component of IMD 120, cause one or more components of IMD 120 toperform various functions attributed to those components in thisdisclosure, including any suitability testing, therapy functions,sensing functions, status monitoring functions, telemetry functions, orthe like. The instructions may be pre-programmed instructions orinstructions received from telemetry module 142 from an external device.

Memory 138 may include any volatile, non-volatile, magnetic, optical, orelectrical media, such as a random access memory (RAM), read-only memory(ROM), non-volatile RAM (NVRAM), static non-volatile RAM (SRAM),electrically-erasable programmable ROM (EEPROM), flash memory, or anyother computer-readable storage media. Processor 140 may include any oneor more of a microprocessor, a controller, a digital signal processors(DSPs), application specific integrated circuits (ASICs),field-programmable gate arrays (FPGAs), or equivalent discrete orintegrated circuitry, including analog circuitry, digital circuitry, orlogic circuitry. The functions attributed to processor 140 herein may beembodied as software, firmware, hardware or any combination thereof.

Telemetry module 142 may receive downlink telemetry from and send uplinktelemetry to another device with the aid of telemetry coupling member148, which may be internal and/or external to IMD 120. During thedelivery and the implantation of IMD 120, telemetry information may beexchanged with an external device (e.g., external device 18) using IMDtelemetry coupling member 148 and telemetry module 142. As describedabove, IMD telemetry coupling member 148 may be communicatively coupledwith the external device via a telemetry coupling member 22 and feedline 16 within the delivery catheter. Although FIG. 19 is described inthe context of antennas, IMD 120 may be communicatively coupled to theexternal device via a different telemetry coupling member, such as atransducer, an electrical connection, a capacitor(s), or the like.

After implantation of IMD 120 within patient 10, IMD 120 may communicatewith an external device 18, or an embodiment such as a programmingdevice. IMD 120 may communicate with external device 18 coupled to thedelivery catheter used to implant IMD 120. For example, IMD 120 andexternal device 18 may communicate using the same communicationtechniques used to communicate between IMD 120 and telemetry device 18,but with different amounts of power consumption. As described above, IMD120 may operate telemetry module 142 in a low power mode (e.g., lowtransmit power and low receiver sensitivity) to communicate with theexternal device 18 when not using the telemetry coupling member as whencoupled to the delivery catheter and operate telemetry module 142 in ahigher power mode (e.g., with a high transmit power and high receiversensitivity relative to the low power mode) to communicate with externaldevice 24. In other instances, the communication techniques between IMD120 and external device 24 may be different than the communicationtechniques used to communicate between IMD 120 and the external devicecoupled to delivery catheter 20, as described further below.

Telemetry module 142 includes any suitable hardware, firmware, softwareor any combination thereof for communicating with another device, suchas programming device 18. For example, telemetry module 142 may includeappropriate modulation, demodulation, encoding, decoding, frequencyconversion, filtering, and amplifier components for transmission andreception of data. In instances in which IMD 120 communicates withexternal device 18 using a different communication technique than usedwhen in the delivery catheter, telemetry module 142 may include morethan one set of telemetry components (e.g., modulation, demodulation,encoding, decoding, frequency conversion, filtering, and amplifier,antenna components or the like), e.g., one set for each type ofcommunication.

Power source 144 contains an energy source for powering the componentswithin IMD 120. Power source 144 may include a rechargeable ornon-rechargeable battery. A non-rechargeable battery may be capable ofholding a charge for several years, while a rechargeable battery may beinductively charged from an external device, e.g., on a daily or weeklybasis. In some instances, power source 144 may harvest energy during theimplantation, e.g., by harvesting the power from the telemetry system inthe telemetry module 142.

IMD 120 may include one or more sensors in addition to electrode 129.The sensors may be located within IMD 120, attached to an externalsurface of IMD 120 or may be remote to IMD 120 and may communicate withIMD 120 wirelessly. In the example of an implantable cardiac pacemaker,IMD 120 may comprise more electrodes which are on the outside of orexternal to IMD 120. Other sensors within IMD 120 may also be utilized,including an accelerometer, a temperature sensor, optical tissue sensoror a GPS receiver. Sensors outside IMD 120 may include electrodesassociated with measuring impedance of various tissues within the body,a pressure sensor, a temperature sensor, a chemical sensor or othersensors.

FIG. 20 is a state diagram illustrating an example set of power statesof an IMD along with transitions between the various power states. FIG.20 will be described with respect to IMD 120 for purposes of discussion.However, IMDs 14, 36, 54, 76, 86, 94 and 104 may operate and transitionbetween similar power states. Upon manufacture 200, IMD 120 is placed inship state 202. As described above, ship state 202 refers to a state inwhich no power is provided to any of the components of IMD 120. Forexample, power switch 146 of IMD 120 may be opened to disconnect powersource 144 from the other components of IMD 120. IMD 120 may beconfigured in the ship state during shipping from a manufacturingfacility to a clinical facility.

IMD 120 may transition from ship state 202 to any of the other states(e.g., transitions 222, 224, or 228) in response to receiving atelemetry signal of sufficient strength. For example, IMD 120 mayharvest power from the telemetry signal and close power switch 146 uponharvesting enough power from the telemetry signal. In other words, IMD120 may power the components of IMD 120 in response to a telemetrysignal of a sufficient strength. In addition, IMD 120 may receive asignal designating the next state into which to configure IMD 120. Thesignal may designate any of the available states, e.g., implant state206, Tele-Hi state 210 or service state 212. Alternatively, IMD 120 maybe configured into a default state upon powering up, such as implantstate 206.

For purposes of discussion, assume that IMD 120 enters implant state 206in which power is provided to some or all of the other components of IMD120. During the implant state, telemetry module 142 operates in a lowpower mode in which a transmitter of telemetry module 142 is set to alow transmit power and/or a receiver of telemetry module 142 is set to alow sensitivity. From the implant state 206, low power telemetry from anadjacent antenna (or other telemetry coupling means) or high powertelemetry from a distant antenna and the appropriate message directs theIMD 120 to transitions 216 or 218.

Tele-Hi state 210 refers to state in which the telemetry module 142operates in a high power mode where the transmitter operates at a higherpower and the receiver operates at a higher sensitivity relative to thelow power state. IMD 120 may, for example, operate in Tele-Hi state 210to allow communication with external device 24 to be tested and verifiedbefore final release of IMD 120 within the body of patient 10. IMD 120may also use the Tele-Hi state 210 when a telemetry session is initiatedafter implantation within patient 10, e.g., during a follow-up session.When the IMD is in Tele-Hi state 210, high power telemetry or a time outwithin IMD 120 causes transition 230 to reach service state 212.

Service state 212 refers to a state in which therapy module 134 andsensing module 136 operate to perform their functions, and telemetrymodule 142 operates in a sleep mode or wakeup mode in which thetransmitter of telemetry module 142 is turned OFF and the receiver oftelemetry module 142 periodically scans for telemetry signals destinedfor IMD 120. By only periodically using the telemetry receiver functionin telemetry module 142 and not using the telemetry transmit function,telemetry module 142 consumes only a small amount of power. A high powertelemetry message may cause IMD 120 to leave service state 212 withtransitions 222, 216 or 230.

FIG. 21 illustrates a block diagram of another example IMD 150 infurther detail. IMD 150 of FIG. 21 is substantially similar to IMD 120of FIG. 19, but includes connectors 152, 154 to receive power from anexternal source during delivery, navigation and implantation of IMD 150.Detachable connectors 152 and 154 are provided to connect to powerconductors within the delivery system catheter.

FIG. 22 illustrates a block diagram of another example IMD 160 infurther detail. IMD 160 of FIG. 22 is substantially similar to IMD 120of FIG. 19, but includes connectors 162, 164 provide externalconnections for telemetry, in a similar manner as described in FIG. 10.As the telemetry circuit can harvest power from the telemetry signals,this embodiment allows the transfer of telemetry and/or power throughthe feed throughs and connectors 162, 164.

FIG. 23 illustrates a block diagram of another example of IMD 170 infurther detail. IMD 170 of FIG. 23 is substantially similar to IMD 120of FIG. 22, but includes telemetry electrodes 166, 168 for conductivelycoupled communication through the body. In some instances, one or bothof telemetry electrodes 166, 168 may be used for conductively coupledcommunication through the body as well as delivery of therapy. In suchinstances, IMD 170 may not include a separate therapy electrode 129.

The techniques described in this disclosure may be implemented, at leastin part, in hardware, software, firmware or any combination thereof. Forexample, various aspects of the techniques may be implemented within oneor more processors, including one or more microprocessors, DSPs, ASICs,FPGAs, or any other equivalent integrated or discrete logic circuitry,as well as any combinations of such components, embodied in programmers,such as physician or patient programmers, stimulators, or other devices.The term “processor” or “processing circuitry” may generally refer toany of the foregoing circuitry, alone or in combination with othercircuitry, or any other equivalent circuitry.

Such hardware, software, or firmware may be implemented within the samedevice or within separate devices to support the various operations andfunctions described in this disclosure. In addition, any of thedescribed units, modules or components may be implemented together orseparately as discrete but interoperable logic devices. Depiction ofdifferent features as modules or units is intended to highlightdifferent functional aspects and does not necessarily imply that suchmodules or units must be realized by separate hardware or softwarecomponents. Rather, functionality associated with one or more modules orunits may be performed by separate hardware or software components, orintegrated within common or separate hardware or software components.

When implemented in software, the functionality ascribed to the systems,devices and techniques described in this disclosure may be embodied asinstructions on a computer-readable medium such as RAM, ROM, NVRAM,EEPROM, FLASH memory, magnetic data storage media, optical data storagemedia, or the like. The instructions may be executed to support one ormore aspects of the functionality described in this disclosure.

Various examples have been described. Although the channel recoverytechniques of this disclosure are described in the context of atwo-staged channel recovery (i.e., same channel recovery followed byunspecified channel recovery), the techniques may be used in a singlestage channel recovery. For example, channel recovery may be performedusing the telemetry wakeup feature immediately after or soon after lossof the communication session is detected. In other words, there may beno same channel recovery performed in the native mode. These and otherexamples are within the scope of the following claims.

1. An implantable medical device delivery system comprising: an elongatecatheter body having a proximal end and a distal end; a first telemetrycoupling member located near the distal end of the catheter body; a feedline coupled to the telemetry coupling member; and an implantablemedical device detachably coupled to the distal end of the catheterbody, wherein the first telemetry coupling member is communicativelycoupled to a second telemetry coupling member of the implantable medicaldevice.
 2. The system of claim 1, wherein the first and second telemetrycoupling members comprise antennas.
 3. The system of claim 2, furthercomprising a conductor that extends along a length of the catheter bodyfrom the proximal end of the catheter body to the distal end of thecatheter body adjacent to the implantable medical device, wherein afirst portion of the conductor forms the feed line and a second portionof the conductor forms the antenna of the first telemetry couplingmember.
 4. The system of claim 1, wherein the first and second telemetrycoupling members comprise transducers that convert electrical signals tononelectrical signals.
 5. The system of claim 1, wherein the first andsecond telemetry coupling members comprise one or more electricalcontacts that electrically couple the feed line and the implantablemedical device.
 6. The system of claim 1, wherein the first and secondtelemetry coupling members comprise one or more capacitive members thatcapacitively couple electrical signals between the feed line and theimplantable medical device.
 7. The system of claim 1, wherein the feedline comprises an optical cable and the first and second telemetrycoupling members optically couple signals between the feed line and theimplantable medical device.
 8. The system of claim 1, wherein the firstand second telemetry coupling members each include at least twoelectrodes that conductively couple signals on the feed line and theimplantable medical device.
 9. The system of claim 1, further comprisingan external device coupled to the feed line at the proximal end of thecatheter body, the external device communicatively coupled to theimplantable medical device via the first and second telemetry couplingmembers.
 10. The system of claim 9, wherein the implantable medicaldevice comprises circuitry to receive a communication signal from theexternal device and to perform an action in response to thecommunication signal.
 11. The system of claim 10, wherein the actioncomprises one of enabling power, changing power, disabling power,changing operating mode, changing operating parameters, changingtelemetry mode, changing communication signal frequency, connectingcircuitry, disconnecting circuitry, sending a communication, and testingsuitability for implant.
 12. The system of claim 9, wherein the externaldevice provides power to the implantable medical device to power atleast a portion of the components of the implantable medical device. 13.The system of claim 9, wherein the external device is coupled to atleast one body electrode on a patient, the external device communicatinga signal through the patient between the at least one body electrode andone of the first and second telemetry coupling members.
 14. The systemof claim 13, wherein one of the external device or the implantablemedical device measures a quality of the communication signal throughthe patient between the at least one body electrode and one of the firstand second telemetry coupling members.
 15. The system of claim 14,wherein the external device reports the communication signal quality toa user of the external device.
 16. The system of claim 14, wherein, theexternal device predicts the communication signal quality ofcommunication with the implantable medical device after implantationbased upon the measured communication signal quality.
 17. The system ofclaim 14, wherein the implantable medical device or the external devicesequentially communicates via one of a plurality of communicationfrequencies.
 18. The system of claim 17, wherein, either the externaldevice or the implantable medical device selects a communicationfrequency based on the measured signal qualities.
 19. The system ofclaim 1, wherein the implantable medical device is a leadlessimplantable medical device.
 20. The system of claim 1 furthercomprising: a conductor extending from the implantable medical device;an electrode coupled to the conductor; an external device; and a controlline detachably coupled to the conductor to electrically couple theexternal device to the electrode.
 21. A method of communicating betweenan external device and an implantable medical device comprising:carrying a communication signal via a feed line that extends between theexternal device and a first telemetry coupling member located within adelivery catheter; and communicatively coupling the communication signalbetween the first telemetry coupling member of the delivery catheter anda second telemetry coupling member of the implantable medical devicethat is detachably coupled to the delivery catheter.
 22. The method ofclaim 21, wherein communicatively coupling the communication signal tothe implantable medical device comprises one of electromagneticallycoupling, capacitively coupling, inductively coupling, opticallycoupling, electroacoustically coupling, electro-optically coupling,acoustically coupling, conductively coupling and mechanically coupling.23. The method of claim 21, further comprising performing an action withthe implantable medical device in response to the received communicationsignal.
 24. The method of claim 23, wherein performing the actioncomprises at least one of enabling power, changing power, disablingpower, changing operating mode, changing operating parameters, changingtelemetry mode, changing communication signal frequency, connectingcircuitry, disconnecting circuitry and testing suitability for implant.25. The method of claim 21, further comprising providing power to atleast a portion of the implantable medical device.
 26. The method ofclaim 21, further comprising communicating a signal through a patientbetween a body electrode on the patient and one of the first and secondtelemetry coupling members.
 27. The method of claim 26, furthercomprising: measuring a quality of the signal communicated between thebody electrode and the one of the first and second telemetry couplingmembers; and reporting the communication signal quality.
 28. The methodof claim 27, further comprising predicting the communication signalquality of communication with the implantable medical device afterimplantation based upon the measured communication signal quality. 29.The method of claim 27, further comprising selecting one of a pluralityof telemetry communication electrodes on the implantable medical devicebased on the measured communication signal quality.
 30. The method ofclaim 29, further comprising: sequentially coupling the communicationsignal to each of the plurality of communication electrodes on theimplantable medical device; measuring a quality of the signalcommunicated between each of the plurality of communication electrodesand a body electrode; and selecting the most optimal electrode of theplurality of communication electrodes on the implantable medical devicebased on the measured signal qualities.
 31. The method of claim 27,further comprising: sequentially generating signals at a plurality ofdifferent communication frequencies for the communication between theimplantable medical device and the external device; measuring thecommunication signal quality for each signal at each differentcommunication frequency; and selecting one of the plurality of differentcommunication frequencies for the communication between the implantablemedical device and the external device based on the measuredcommunication signal qualities.
 32. An implantable medical devicedelivery system comprising: means for communicatively coupling acommunication signal with an implantable medical device that isdetachably coupled to a catheter; and means for carrying a communicationsignal between a proximal end of the catheter and the coupling meanslocated within the catheter.
 33. The system of claim 32, wherein, thecoupling means communicatively couples the communication signal and theimplantable medical device via one of electromagnetic coupling,capacitive coupling, conductive coupling, inductive coupling, opticalcoupling, electroacoustic coupling, electro-optical coupling, acousticcoupling and mechanical coupling.
 34. The system of claim 32, furthercomprising means for performing an action with the implantable medicaldevice in response to the received communication signal.
 35. The systemof claim 32, wherein the coupling means communicatively couples a signalbetween a body electrode on a patient and the implantable medicaldevice, the device further comprising means for measuring a quality ofthe signal communicated between the body electrode and the couplingmeans.